second relfection bug?

[NiGMa]

Hi, is this a bug? I can't seem to get rid of it. I have checked and there are no overlapping polys.

Am i correct in saying that this is rendered wrong?

[Captain Obvious]

Looks reasonable to me. Glass usually produces two reflections.

[jure]

You're probably using double sided surface flag. This would cause reflection ray see the polygon even if it's facing away.

[NiGMa]

nope, im only using "recurse=10", it looks worse on glass bals and glass sliding doors, its definiately not physically accurate.

[acidarrow]

Are you using air polys? Since kray doesn't need air polys having them could have weird results I guess.

Can you make a texture-less scene that replicates this behavior and post it here?

[NiGMa]

no air polys, I will make a scene. gimme say... 360secs. hehe

[NiGMa]

Wow, look at these. without the "lwo2airpoly" switch turned on, it renders wrong. I only have outer polys no inner, so the top piece of glass is only 29polys total, with beveled edges.

Am I understanding kray incorrectly or is this a bug, I thought the lwo2airpolys was only if you have outer polys plus air polys?

hmm.. what do you guys think? also look at the render times! no wonder my renders have been so slow lately!

[acidarrow]

(moved my answer from the other thread here)

I got the scene from the other thread and played around with it.

I confirm the double reflection. I made the scene even more minimal and it still happens. So, it seems that the air polys that (I am assuming) kray adds have some reflective properties, maybe to simulate/fake the internal reflection happening, I am not sure.

The thing is, if the refraction index is the same for both materials (the glass in scene has nd 1 same as air) there is no internal reflection happening, none at all. (go to http://www.phy.ntnu.edu.tw/oldjava/optics/prism_e.html and put nd 1 to both materials).

So the only way to not have the second reflection happen is to use lwo2airpolys which I am assuming switches to the lightwave model which needs air polys, so kray doesn't add its own.

I believe this is a bug. If it is not, some explanation on how kray handles glass is needed.

[NiGMa]

Looks reasonable to me. Glass usually produces two reflections.

YOU ARE RIGHT!

I was on the toilet yesterday, and was looking at a reflection in the shower glass and it there were two! I was surprised!

So, this is not a bug.